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Consequences of alternative functional response formulations in models exploring whale-fishery interactions
Citation
Mackinson, S and Blanchard, JL and Pinnegar, JK and Scott, R, Consequences of alternative functional response formulations in models exploring whale-fishery interactions, Marine Mammal Science, 19, (4) pp. 661-681. ISSN 0824-0469 (2003) [Refereed Article]
Copyright Statement
British Crown copyright 2003
DOI: doi:10.1111/j.1748-7692.2003.tb01123.x
Abstract
We evaluated the utility of Ecosim for exploring interactions between cetacean
predators, their prey, and fisheries. We formulated six Ecosim parameterizations,
representing alternative hypotheses of feeding interactions (functional response)
between cetaceans and their main fish prey, and examined differences in the
predicted responses to simulated harvesting regimes for minke whales and their
prey. Regardless of the type of function response formulated, intense fishing on the
main fish prey of minke whales had a longer-lasting negative impact on minke
whales than when minke whale biomass was removed directly by harvesting.
Consumption rate, biomass, feeding time and mortality of minke whales were all
sensitive to the type of functional response specified. Inclusion of ‘‘handling time’’
limited minke whales consumption at high prey densities and predicted higher
consumption at low prey densities; features characteristic of a type II functional
response. Predicted decline and recovery rates of minke whales were slower than
when consumption rates were not limited. Addition of ‘‘foraging time’’ adjustments
resulted in more conservative estimates of decline and recovery. However,
when ‘‘other mortality’’ was linked to time spent foraging, exposure to higher
mortality at low prey densities, and reduced mortality at high prey densities resulted
in dramatic differences in predicted biomass trajectory. Sensitivity to the ‘‘other
mortality’’ assumption is important for cetaceans whose predation mortality is only
a small proportion of total mortality. Differences in the feeding and biomass
dynamics were also observed when prey availability to predators was represented
by changes in prey vulnerability, confirming earlier reports that Ecosim predictions
are sensitive to this parameter.
Item Details
Item Type: | Refereed Article |
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Keywords: | ecosystem modelling, food webs, conservation, fisheries |
Research Division: | Biological Sciences |
Research Group: | Ecology |
Research Field: | Community ecology (excl. invasive species ecology) |
Objective Division: | Environmental Management |
Objective Group: | Management of Antarctic and Southern Ocean environments |
Objective Field: | Assessment and management of Antarctic and Southern Ocean ecosystems |
UTAS Author: | Blanchard, JL (Professor Julia Blanchard) |
ID Code: | 100515 |
Year Published: | 2003 |
Web of Science® Times Cited: | 45 |
Deposited By: | Sustainable Marine Research Collaboration |
Deposited On: | 2015-05-18 |
Last Modified: | 2015-06-17 |
Downloads: | 0 |
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